--- title: Reading signals slug: zero/sub-ghz/read description: Reading and sending procedures and configurations of the Read function image: https://archbee-image-uploads.s3.amazonaws.com/3StCFqarJkJQZV-7N79yY/VN-zouD_8ktLiJ-bLYfDy_readingsignalspreview1.png docTags: createdAt: 2022-07-28T09:15:52.000Z --- ![](https://api.archbee.com/api/optimize/3GUDYkC5JgUWgo6RW8piO-c0M5DM4ySGJfJGLDo4yLo-20241024-180047.png) With your Flipper Zero, you can read, save, and emulate different types of remote controls with known protocols. There are remote controls that work on protocols that Flipper Zero doesn’t know yet. Signals from these remotes can be recorded in raw format, saved, and replayed with the [Read RAW](https://docs.flipper.net/zero/sub-ghz/read-raw) function. We constantly update and improve the Flipper Zero firmware with the help of our community. To make your contribution to helping Flipper Zero support more remotes, you can leave information about your remote [](https://forum.flipperzero.one/t/my-remote-isnt-supported-how-to-add-new-sub-ghz-protocol-in-flipper-zero/2033)on the [forum](https://forum.flipperzero.one/t/my-remote-isnt-supported-how-to-add-new-sub-ghz-protocol-in-flipper-zero/2033). On this page, you’ll learn how to read and emulate remote controls, determine a remote’s frequency, and receive signals at unknown frequencies. This article also explains what to do if Flipper Zero is unable to read the signal with default settings and provides an overview of the Bin\_RAW and Lock Keyboard features. *** # How to read signals In Read mode, Flipper Zero reads and decodes demodulated signals from remote controls based on known protocols. If the remote’s protocol is static, Flipper Zero can save and send the signal. To read and save the signal from your remote control, do the following: :::::WorkflowBlock :::WorkflowBlockItem Go to **Main Menu** **->** **Sub-GHz**. ::: :::WorkflowBlockItem Press **Read**, then press the button on the remote control you want to read. ![](https://api.archbee.com/api/optimize/3StCFqarJkJQZV-7N79yY/3LARdEupzZR64-chUzbPH_monosnap-miro-2023-07-14-12-19-41.jpg "Scanning screen") ::: :::WorkflowBlockItem When the signal is captured, press %ok%**OK**, then press **Save**. ![](https://api.archbee.com/api/optimize/3StCFqarJkJQZV-7N79yY/oSgQs07b-5ukhIV49qyaX_monosnap-miro-2023-07-12-19-43-57.jpg "Types of captured signals") ::: ::::WorkflowBlockItem Name the captured signal, then press **Save**. :::Iframe{code="" iframeHeight="0"} ::: :::Iframe{iframeHeight="0" code="
Remotes have different frequencies and modulations
To read signals correctly, you need to know the remote control’s parameters and configure your Flipper Zero accordingly. If Flipper Zero is unable to read the signal with the default settings, you will need to interact with Frequency and Modulation parameters in the Configuration Menu.
"} ::: :::: ::::: *** # Configuration Menu In this menu, you can switch frequencies manually and in Hopping mode, switch modulations manually, and lock the keypad while scanning for signals. To open the Configuration Menu, on the scanning screen, press **Config**. You will see the following: ::Image[]{src="https://api.archbee.com/api/optimize/3StCFqarJkJQZV-7N79yY/ayaJKt_oZ7ZE8eP619laK_monosnap-miro-2023-07-14-16-27-45.jpg" size="90" width="2050" height="764" position="center" caption="Configuration screen" showCaption="true"} *** ## Frequency configuration You can switch frequencies at which Flipper Zero receives signals. In the **Configuration Menu**, by pressing %left%**LEFT** or %right%**RIGHT** you can manually set frequencies from the list: ![](https://cdn.flipperzero.one/Monosnap_Miro_2022-08-23_14-24-29.png "List of configuring frequencies") To read the signal correctly, it is necessary to determine the frequency of the remote. For that, you can use the Frequency Analyzer feature. *** ### Frequency Analyzer When analyzing, Flipper Zero is scanning signal strength at all the frequencies available in the Configuration Menu. Flipper Zero displays the frequency with the highest received signal strength indicator (RSSI) value, with signal strength higher than -90 [dBm](https://en.wikipedia.org/wiki/DBm). To determine the remote’s frequency, do the following: :::::WorkflowBlock ::::WorkflowBlockItem Place the remote control very close to the left of your Flipper Zero. ::Image[]{src="https://api.archbee.com/api/optimize/3StCFqarJkJQZV-7N79yY/nR_6aWyXoMwgfH-_fo2Ff_image.png" size="80" width="2620" height="1194" caption="Place the remote to the left of your Flipper Zero" position="center" showCaption="true"} :::Iframe{code="
It is important to place the remote very close to your Flipper Zero to avoid analyzing signals from other devices.
" iframeHeight="0"} ::: :::: :::WorkflowBlockItem Go to **Main Menu** **-> Sub-GHz -> Frequency Analyzer**. ::: :::WorkflowBlockItem On your remote control, press and hold the button you want to analyze. ::: :::WorkflowBlockItem Review the measured frequency value on the screen. ::: ::::: By pressing the %left%**LEFT** or %right%**RIGHT** button, you can go to the second screen that shows up to 15 measured frequencies. On the second screen, you can sort measured frequencies by pressing the %ok%**OK** button. ![](https://api.archbee.com/api/optimize/3StCFqarJkJQZV-7N79yY/Gmsu49H4Ga7x6aWwbLWBO_image.png "The Frequency Analyzer feature has two screens") :::Iframe{code="
The analysis results can be approximate
Flipper Zero displays values that can help you to determine the frequency band in which the signal is sent. In most cases, the signals are sent at frequencies in 315, 433, and 868 MHz bands.
" iframeHeight="0"} ::: *** ## Hopping between frequencies To receive a signal at an unknown frequency, use Hopping mode. In this mode, Flipper Zero switches quickly between the available frequencies and measures the signal strength. Once the signal strength exceeds -90 dBm, switching stops and Flipper Zero receives the signal at that frequency for one second, then switching between frequencies resumes. To scan for signals in Hopping mode, in the **Configuration Menu**, set **Hopping** to **ON**. :::Iframe{code="" iframeHeight="0"} ::: :::Iframe{code="
Switching between frequencies takes some time, therefore signals transmitted at the time of switching can be missed. For better signal reception, set a fixed frequency determined by Frequency Analyzer.
" iframeHeight="0"} ::: In Hopping mode, you can also manually switch modulations. *** ## Modulation configuration To capture the signal from the remote control, you need to configure the correct modulation settings on your Flipper Zero. Because Flipper Zero is not a software-defined radio, you need to configure the right modulation before scanning the signal, otherwise, you will not receive the correct data. Flipper Zero supports [Amplitude (AM)](https://en.wikipedia.org/wiki/Amplitude_modulation) and [Frequency (FM)](https://en.wikipedia.org/wiki/Frequency_modulation) signal modulations. In the **Configuration Menu**, by pressing %left%**LEFT** or %right%**RIGHT**, you can manually set signal modulations from the list: - **AM270:** amplitude modulation with the bandwidth of 270 kHz. - **AM650:** amplitude modulation with the bandwidth of 650 kHz (set as default). - **FM238:** frequency modulation with the bandwidth of 270 kHz and the [deviation](https://www.youtube.com/watch?v=gFu7-7lUGDg\&t=142s) of 2.380371 kHz. - **FM476:** frequency modulation with the bandwidth of 270 kHz and the deviation of 47.60742 kHz. *** ## Bin\_RAW This option allows the processing of RAW signals that weren’t decoded during the reading process. The processing involves eliminating background noise, removing repeating signal segments, and correcting timing errors. To use this feature, you need to enable the Bin\_RAW option manually. Additionally, it is important to verify that the frequency and modulation parameters align with your remote control for optimal functionality. *** ## Lock Keyboard This function allows you to lock the keypad while your Flipper Zero is scanning for signals. To lock the keypad, in the **Configuration Menu**, select **Lock Keyboard** and press %ok%**OK**. *** # Sending signals Flipper Zero can send saved signals that are recorded at frequencies that are allowed for transmission in your region. To send a saved signal with Flipper Zero, do the following: ::::WorkflowBlock :::WorkflowBlockItem Go to **Main Menu** **->** **Sub-GHz** **->** **Saved**. ::: :::WorkflowBlockItem Select the signal, then press **Emulate**. ::: :::WorkflowBlockItem Press **Send** to send the saved signal. ::: :::: :::Iframe{code="
Some frequencies can be blocked for transmission in your region
Flipper Zero can receive signals at all frequencies in the operational bands. However, Flipper Zero can transmit signals only at frequencies that are allowed for transmission in your region.
" iframeHeight="0"} ::: To learn more about regions and allowed transmitting frequencies, visit the [Frequencies](https://docs.flipperzero.one/sub-ghz/frequencies) page. *** # Listening to walkie-talkies Did you know that you can listen to analog walkie-talkies with your Flipper Zero’s buzzer? While not originally intended, the Sub-GHz Read and Read RAW features enable this functionality. :::Iframe{iframeHeight="0" code="
This feature may not work well
Flipper Zero is designed to receive digital signals. When it receives an FM-modulated analog radio signal, the device processes it as digital data, interpreting frequencies above a certain threshold as 1s and below as 0s. Additionally, the buzzer in Flipper Zero isn’t designed for human voice playback. To use this feature effectively, speak loudly enough into the walkie-talkie.
"} ::: To start listening to a walkie-talkie: ::::WorkflowBlock :::WorkflowBlockItem Go to **Main Menu -> Sub-GHz**. ::: :::WorkflowBlockItem Select: - **Read** — to listen only. * or* - **Read RAW** — to listen and record. ::: :::WorkflowBlockItem Go to **Config**. ::: :::WorkflowBlockItem Set **Frequency** to the frequency of the walkie-talkie you want to listen to. ::: :::WorkflowBlockItem Set **Modulation** to **FM238**. ::: :::WorkflowBlockItem Set **Sound** to **ON**. ::: :::WorkflowBlockItem (Optional) If you’ve selected **Read RAW**, you can also configure **RSSI Threshold** to only record signals that exceed the set signal strength level. [Learn more about RSSI Threshold configuration.](https://docs.flipper.net/zero/sub-ghz/read-raw#yDGEq) ::: :::WorkflowBlockItem Press %back%**BACK**. ::: :::WorkflowBlockItem If you’ve selected **Read RAW**, press %ok%**OK** to start listening. ::: :::: All set up. Now, if the person at the other end speaks loudly enough, you’ll be able to hear their voice via your Flipper Zero’s buzzer.